Craigslist is great for finding a good deal, but it's filled with scammers. Redditor lifedeathandtech suggests one way to weed out scammers is to do a reverse image search of pictures in their posting to see if they just lazily pulled pictures off the web.

Since any Craigslist user should have the product they're selling in their hand, they should be able to take a picture of it. If they can't, they've likely just grabbed some random picture off of Google. So, if a deal looks too good to be true, or if a seller just seems like they're scamming you, download the image off Craigslist, and drag-and-drop it into Google Images (or downloads the Search by Image extension for Chrome or Firefox) to see if it appears elsewhere. It doesn't necessarily guarantee they're a scammer, but it can help you sort through some of the junk postings. While you're at it, a few Redditors also suggest searching Craigslist for the phone number the seller lists to see other listings by the same seller. A little investigation can go a long way to keep you from wasting time on a scam.